1. Field of the Invention
The present invention is related to personal computers and more particularly to an improved motherboard apparatus of a personal computer.
2. Background Art
A personal computer is a stand-alone desktop computer housed in a chassis which is a cover that protects the computer components from the environment and the environment from the computer, such as electromagnetic interference (EMI). Input/output (I/O) devices, such as a video monitor, mouse and printer are connected by means of cables that plug into connectors at a back panel of the chassis. Inside the chassis is a system board, called a motherboard, that holds the electronic components of the computer. Expansion add-in cards are inserted into up to eight connectors that are mounted directly on the motherboard. The motherboard has printed circuit wiring that distributes signals from the add-in cards to appropriate components on the motherboard via an expansion bus.
Today, two primary motherboard standards exist. The Baby AT (BAT), and the Low Profile expandable (LPX). BAT was established by IBM at the inception of the IBM personal computer AT (Advanced Technology). LPX was developed later by Western Digital.
The BAT motherboard dimensions are 8.6" by 13" and contains up to 8 vertical slots for expansion cards. The BAT motherboard has the advantage that it is very common, it is easy to insert add-in cards and the design places the central processing unit (CPU) module near the front of the chassis where it is cooled by incoming air. The BAT motherboard has the disadvantage that there is no expansion room for additional I/O connectors out the back of the motherboard. Also, the CPU and its heat sink, and single in-line memory modules (SIMMs) cut off full length expansion slots.
The LPX motherboard dimensions are 9' by 13' and contains 5 horizontal slots for expansion cards. The LPX motherboard has the advantage that it is common. I/O is integrated on the motherboard and easily goes out the back of the chassis and the CPU usually placed near the front of chassis where it is cooled by incoming air.
The LPX motherboard has the disadvantage that add-in cards are harder to install and a riser card is required in the center of the motherboard to support expansion slots. Also, the CPU and its heat sink, and the SIMMs cut off full length expansion slots.
It is therefore desirable to have an improved motherboard that results in lower total system cost and adds some new capabilities to keep up with increasing I/O needs of modern multimedia computers.